The incorporation of gas under a pressure of more than 2 bars in a liquid or paste enables substantial quantities of gas to dissolve and which are subsequently trapped in the matrix on deep-freezing.
This incorporation of gas can be carried out with nitrogen, nitrous oxide, carbon dioxide, a noble gas such as argon or a mixture of these gases.
Various devices have already been described for adding gas into a food-grade or non food-grade matrix.
Thus, a device for creating mini-bubbles in a liquid is described in the patent EP 1 594 599. The device comprises a gas/liquid mixing space that communicates with a gas inlet and a disk, and means for bringing the gas/liquid mixture into contact with one of the faces of the disk.
A device for the preparation of a spumescent liquid with gaseous oxygen is described in the patent EP 1 486 129. This device operates under pressure and aseptically generates and stabilises the bubbles in the liquid.
Deep-freezing is a known method for preserving foods or non-foodstuffs for very long periods, without significantly modifying them.
Thus, a device for slowly deep-freezing immiscible droplets comprised in a liquid having a temperature gradient going from ambient temperature to below the freezing point of the liquid is described in the patent GB 1 304 045.
A device for condensing coffee aromas by means of a cryogenic liquid is described in the patent EP 201 698. A process for deep-freezing fruit juices for the production of frozen beads without gasification is described in the patent ES 2194558.
A general method for the cryogenic deep-freezing of non-gasified frozen dessert particles is described in the U.S. Pat. No. 6,349,549.
A production process for particles of a frozen product after gasification under high pressure, i.e. above 1000 bar, is described in the patent JP 0420203869.